Fix Bad Spelling in Any Application with Enso Words (Windows)
From blog posts to brochures to text messages, spelling errors have no place in professional communications. Unfortunately, while most word processors have their own spell-checkers, few other programs do. Enso Words is a universal spell-checker, meaning it works in any application. Use it to fix bad spelling in e-mails, blog entries, instant messages, and so on.
The program provides not only pop-up spell-checking, but also word definitions, word and character counts, and a thesaurus. Enso Words is free; it requires Windows 2000, XP, or Vista. [via Office Tweaks]